Microgrids for Commercial Systems

Book excerpt: MICROGRIDS for COMMERCIAL SYSTEMS This distinct volume provides detailed information on the concepts and applications of the emerging field of microgrids for commercial applications, offering solutions in the design, installation, and operation of this new, cutting-edge technology. The microgrid is defined as Distributed Energy Resources (DER) and interconnected loads with clearly defined electrical boundaries that act as a single controllable entity concerning the grid as per IEEE standard 2030.7-2017. It provides an uninterrupted power supply to end-user loads with high reliability. Commercial systems like IT/ITES, shopping complexes, malls, the banking sector, hospitals, etc., need an uninterrupted input power supply with high reliability. Microgrids are more suitable for commercial systems to service their clients with no service discontinuity. The microgrid enables both connection and disconnection from the grid. That is, the microgrid can operate both in grid-connected and islanded modes of operation. The microgrid controller plays an important role in microgrid systems. It shall have an energy management system and real-time control functions that operate in the following conditions: both grid-connected and islanded modes of operation, automatic transfer from grid-connected mode to islanding mode, reconnection and re-synchronization from islanded mode to grid-connected mode, optimization of both real and reactive power generation and consumption by the energy management system, grid support, ancillary services, etc. Whenever a microgrid is in islanded mode, it will work as an autonomous system without a distribution grid power supply. In this mode of operation, fault in the transmission or distribution grid will not propagate into the microgrid. Whenever a microgrid operates in grid-connected mode, power flows bi-directionally between the distribution grid and microgrid at the point of interconnection. Hence, microgrids ensure the interrupted power supply to the end-user loads with high reliability. This book aims to bring together the design, installation, operation, and new research that has been carried out in the field of microgrid applications for commercial power systems.